Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Cisco Catalyst 6500 Virtual Switching System (VSS) design - Layer 2/3

Posted on 2011-09-25
3
Medium Priority
?
917 Views
Last Modified: 2012-05-12
Cisco's Virtual Switching System (VSS) in the Catalyst 6500-series is a Layer 2 technology. The customer (currently w/ a non-VSS dual-core design), is routing at the edge - meaning, they have Cisco 3750 stacks in the closets configured for Layer 3 links (point-to-point /30 subnets between the closets and the core). They're dual-homed to each parent switch (again, non-VSS), so there's EIGRP load-balancing between the two equal-cost uplinks.  My questions:

Is it possible/feasible to deploy a unified VSS core design w/ L3 distribution links, or should VSS only be rolled out in environments w/ L2-only access closets?
Given that the customer already has L3 switching at the edge (w/ load-balancing across the dual-homed uplinks), does a VSS core really offer any benefit, performance/scalability-wise?
Thank you - reference links/docs are always appreciated.








0
Comment
Question by:cfan73
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 50

Accepted Solution

by:
Don Johnston earned 2000 total points
ID: 36597758
There are a couple schools of thought on this.

1) With layer 2 links, without VSS (and links to both 6500's that have been channeled), spanning tree will block all but one path. This makes VSS a no-brainer.

2) With layer 3 links, the load balancing is being handled by the routing algorithm. Which will be at least as good as the etherchannel algorithim.

3) Without VSS, there are two separate devices to be managed. With VSS, there is (effectively) one.

As for which is best, that depends on your definition of "best". :-)
 
0
 

Author Comment

by:cfan73
ID: 36598927
Thanks for the input, Don. It sounds as if the only benefit VSS would offer in a L3 routed environment would be the single IP management (much like a 3750 switch stack), which would be tough (for me) to justify wasting multiple 10-GE ports on each chassis just for this.  

Do you know if the same reasoning would apply to vPC (Virtual Port Channels) on the Nexus side, where there would be no reason to implement this in a routed L3 environment?


0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 36598951
>which would be tough (for me) to justify wasting multiple 10-GE ports on each chassis just for this.  

If you've already got the sup's in place and you're not using them, I don't see a downside to VSS.

>Do you know if the same reasoning would apply to vPC

Yes.
0

Featured Post

What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Microservice architecture adoption brings many advantages, but can add intricacy. Selecting the right orchestration tool is most important for business specific needs.
In this article, we’ll look at how to deploy ProxySQL.
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
Suggested Courses

604 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question